Adjustable air gauging mandrel



United States Patent 3,154,939 ADJUSTABLE AIR GAUGING MANDREL Karnig H. Dahanian, 13137 Balfour, Huntington Woods,

Mich, and William H. Kirk, 1109 W. Selfridge, Clawson, Mich.

Filed 0st. 8, 1962, Ser. No. 229,043 6 (Jlaims. (Cl. 7337.9)

The present invention relates to air gauging systems and more particularly to an air gauge mandrel adapted for use with such systems and having means permitting the diameter of the mandrel to be adjusted to measure a wide range of different size workpieces.

Air gauging systems are used quite extensively to gauge the inside dimensions of workpieces. An air plug is inserted into the workpiece and a constant pressure is provided through jets radially disposed in the air plug. Changes in pressure produced by variations in the size of the workpiece are noted on a pressure or air flow responsive indicator. The distance between the jets and the workpiece must be relatively small to insure an accurate reading. This requires that difierent size air plugs be provided for each different size workpiece. Although adjustable mandrels have been recently provided for such systems, these have been found to have several important disadvantages which are overcome by the adjustable mandrel of the present invention. Due to complex structure such adjustable mandrels as are now being produced are quite expensive and difiicult to use. Also the range of adjustability is quite limited.

It is an object of the present invention then to reduce the cost of air gauging workpieces by providing a simply constructed air gauging mandrel having means securely locking radially adjustable shoes in the desired adjusted position.

It is still another object of the present invention to increase the range of adjustment of air gauging mandrels by providing a slotted body member and a number of different sets of readily removable and radially adjustable shoes carried in the slots of the body member, each set of shoes being capable of being radially adjustable over a different range of dimensions.

For more complete understanding of the present invention, reference should be made to the following drawings in which like reference characters refer to like parts throughout the several views and in which FIG. 1 is an elevational side view of a mandrel of the present invention.

FIG. 2 is a longitudinal cross sectional view taken sub stantially on line 22 of FIG. 1.

FIG. 3 is an end view as seen substantially from line 3-3 of FIG. 1.

FIG. 4 is an elevational top view of an orifice shoe of the present invention, and

FIG. 5 is a cross sectional view taken substantially on line 55 of FIG. 4.

Now referring to the drawings for a more detailed description of the present invention, FIGS. 1-3 illustrate a preferred air-gauging mandrel of the present invention as comprising a substantially cylindrical body member 19. The body member 11) preferably comprises threaded portions 11-12 separated by an enlarged central portion 13. One end of the body member 11) is provided with a fluid inlet 14 adapted for connection to any suitable pressure supply and gauging system (not shown). An axially extending central passage 15 as can best be seen in FIG. 2 provides communication between the inlet 14- and a transverse passage 16 provided in the central portion 13.

The body member 11) is provided with pairs of axially extending equally annularly spaced slots 17a and 17b.

The slots 17a-17b as can best be seen in FIG. 2 are uniformly sloped with respect to the axis of the body member 10. The slots 17a are preferably somewhat larger in transverse cross sectional area than the slots 17b as can best be seen in FIG. 3.

Orifice shoes 18 are longitudinally slidably carried in the slots 17a. As can best be seen in FIGS. 3, 4 and 5, each orifice shoe 18 is provided with conical end faces 19, a top surface 21 arcuate about a selected longitudinal axis A-A as indicated in FIG. 5, and a bottom cam surface 22 sloped with respect to the aforesaid longitudinal axis AA. An orifice 23 is provided in the shoe 18 and an annular recess 24 is disposed in the top surface 21 concentric to the orifice 23 to provide an annular land 25. Elongated recesses 26 are provided in the central portion 13 of the body member 19 in a position to provide communication between the passage 16 and the orifices 23. O-ring seals 27 substantially eliminate leakage between the shoes 18 and the body member 10.

Locating shoes 28 are carried in the slots 17b and are substantially similar in construction to the orifice shoes 18 except that they are not as wide and have no orifices. The locating shoes 28 as can best be seen in FIGS. 1 and 3 preferably have an arcuate top surface 29 having the same radius as the surface 21 of the shoe 18, a bottom cam surface 3% sloped similarly with respect to the surface 22 of the shoe 18, and conical end faces 31.

Nut members 32 are carried on the threaded portions 11-12 of the body member 10. The nut members 32 are each provided with a conical seat portion 33 which engages with the conical end faces 12 and 31 of the orifice shoes 18 and locating shoes 28 respectively to lock the shoes 18-28 in a predetermined longitudinal position on the body member 10.

In operation the air gauge mandrel of the present invention is connected to a suitable air pressure supply and gauging system (not shown). An appropriate set of orifice shoes 18 and locating shoes 28 are positioned in the slots 17a and 171) respectively and the nut members 32 are tightened to engage the shoe members 18 and 28. The mandrel, with fluid pressure supplied, is then inserted in one or more master calibrating rings and the nut members 32 are rotated to adjust the shoes 18-23 to the desired longitudinal position on the body member 10, and the pressure gauge (not shown) is set to zero. As the nut members 32 are adjusted, a corresponding radially outward or inward movement of the shoes 18-28 is produced due to the coaction of the cam surfaces 22-30 and the slots I'M-17b. The mandrel is now ready for use in gaging the bore diameter of a workpiece.

The seals 27 insure the gauging will not be in error due to pressure bypassing the orifices 23 and the recesses 26 provide communication to the orifices 23 over a wide range of axial adjustment of the shoe members 18.

It will be apparent from the foregoing description that a single body member 10 can be used to accommodate shoe members 18 and 28 of various sizes so that a set may be assembled capable of use with workpieces having a wide range of different diameters. In production of air gauging mandrels of the present invention varying sets of shoes 18-28 will be provided for body member 10.

The threaded portions 11-12, the slots 17a-17b and the cam surfaces 22-30 of the shoes 18-28 have been constructed to produce a radially inward or outward displacement of the shoes 18-28 of inch for each major graduation provided on the nut members 32.

The conical end faces 18-31 and the d r iical seat portions 33 of the nut members 32 provide a means of securely locking the shoes 18-28 in the desired longitudinal position.

3 It is also apparent that although we have described but one embodiment of'th'e'present invention, many changes and modifications may be made without departing from surface engaging in said slot whereby as said shoe member is moved longitudinally with respect to said body member radially inward and outward displacement of said shoe member is produced,

(f) means selectively adjusting and locking said shoe members in a predetermined longitudinal position with respect to said body member,

(g) said body member being provided with a fluid inlet and a central chamber communicating therewith, and

(h) at least one of said shoes being provided with aradially extending orifice communicating with said central chamber.

2. The gauging member as defined in claim 1 and in which said adjusting and locking means comprises,

(a) a threaded outer surface being provided on said body member,

(b) a pair of longitudinally spaced nut members adjustably carried by said threaded surface,

(0) each of said shoe members having a conical face at each end,

(d) said nut members each having a conical seat engaging said conical faces of said shoe members whereby as said nut members are longitudinally adjusted with respect to said body portion said shoe members are thereby slidingly moved with respect to said body portion to a predetermined position and as said conical seats of said nut members are urged to bear against said conical faces of said shoe members, said shoe members are securely locked in position.

3. A gauging member for use in a fluid gauge system comprising (a) a substantially cylindrical body member,

(b) said body member having a central portion and a pair of spaced threaded end portions,

(c) a plurality of longitudinal annularly spaced ra dially extending slots being provided in said body portion,

((1) said slots being longitudinally tapered with respect to the axis of said body member,

(2) a nut member axially adjustably carried on each of said threaded end portions,

(f) a shoe member longitudinally adjustably removably carried in each of said slots by said nut members,

(g) said shoe members each having a cam surface engaging with said body member whereby as said shoe members are moved axially with respect to said body member said shoe members are moved radially outwardly and inwardly with respect to the axis of said body member,

(h) a pair of said shoe members each being provided with a radially extending orifice,

(i) one end of said body member being provided with a fluid inlet adapted for connection to a fluid source and (j) an axially extending chamber provided in said body member communicating between said inlet and said orifices.

4. The gauging member as defined in claim 3 and in which (a) said nut members are each provided with an axial conical seat portion, and

(b) said shoe members are each provided with conical end portions engaging in said seat portions whereby said shoe members may be securely locked in any predetermined axial position.

5. The gauging member as defined in claim 4 and in which (a) said central portion is provided with a pair of annularly spaced longitudinally elongated recesses,

(b) said recess being disposed to provide communication between said chamber and said orifices at all longitudinal positions of said shoe members.

6. The gauging member as defined in claim 5 and including an O-ring seal'disposed in each of said recesses and having a portion bearing against said shoe members provided with said orifices.

No references cited. 

1. A GAUGING MEMBER FOR USE IN A FLUID GAUGE SYSTEM, SAID MEMBER COMPRISING (A) A SUBSTANTIALLY CYLINDRICAL BODY MEMBER, (B) A PLURALITY OF LONGITUDINAL ANNULARLY SPACED RADIALLY EXTENDING SLOTS PROVIDED IN SAID BODY MEMBER, (C) SAID SLOTS BEING LONGITUDINALLY TAPERED WITH RESPECT TO THE AXIS OF SAID BODY MEMBER, (D) A SHOE MEMBER LONGITUDINALLY SLIDABLY CARRIED IN EACH OF SAID SLOTS, (E) SAID SHOE MEMBERS EACH HAVING A TAPERED BOTTOM SURFACE ENGAGING IN SAID SLOT WHEREBY AS SAID SHOE MEMBER IS MOVED LONGITUDINALLY WITH RESPECT TO SAID BODY MEMBER RADIALLY INWARD AND OUTWARD DISPLACEMENT OF SAID SHOE MEMBER IS PRODUCED, (F) MEANS SELECTIVELY ADJUSTING AND LOCKING SAID SHOE MEMBERS IN A PREDETERMINED LONGITUDINAL POSITION WITH RESPECT TO SAID BODY MEMBER, (G) SAID BODY MEMBER BEING PROVIDED WITH A FLUID INLET AND A CENTRAL CHAMBER COMMUNICATING THEREWITH, AND (H) AT LEAST ONE OF SAID SHOES BEING PROVIDED WITH A RADIALLY EXTENDING ORIFICE COMMUNICATING WITH SAID CENTRAL CHAMBER. 